This application is a continuation of co-pending International patent application PCT/EP00/03934, filed May 2, 2000, designating the United States and claiming priority from German patent application No. 199 19 941.8, filed Apr. 30, 1999.
The invention relates to new S- nitroso- and S-nitro-N-acyl-L-cysteine ester derivatives (SNACE derivatives) as pharmacologically active agents and pharmacological compositionsxe2x80x94in particular for transdermal applicationxe2x80x94which contain a SNACE derivative, for the prevention and treatment of a series of diseases including peripheral occlusive diseases, of the myocardial infarction, angina pectoris, the ischemic stroke, arteriosclerotic vascular changes, thrombosis (inhibition of the platelet aggregation), homocysteinemia, and impotentia coeundi, disfunctional miction, asthma bronchial, hypertonia, pulmonic hypertonia, diabetic nephropathy, mucoviscidosis, cancer and Alzheimer""s disease.
A variety of vasolidators are known which can be used for the treatment of hypertensive conditions, of angina pectoris, of impotentia coeundi, thrombosis and other diseases. These pharmaceutical compositions can be divided into different categories according to the mechanism of their primary effect. Three important groups of these pharmaceutical compositions are the inhibitors of the angiotensin converting enzyme (ACE), the organic nitrates and nitrogenmonoxide (NO) donors. Whereas neither ACE inhibitors nor the organic nitrates such as e.g. glyceryl trinitrate (GTN) are anti-aggregatory active substances which are clinically significant, some NO donors including the S-nitroso substances (RSNO) can have both an antihypetensive and an anti-aggregatory effect.
Contrary to the organic nitrates which are effective only after their metabolisation in the cells resulting in active intermediates, S-nitroso compounds have an effect without prior enzymatic activation either directly or after release of NO. Ignarro et al. (Biochem. Biophys. Acta, 631 (1980) 221-231) have shown that the S-nitroso-compounds of cysteine, glutathion, penicillamine and dithiothreitol are able to directly activate the soluble guanylate cylase (sGC). The effect of organic nitrates, sodium nitrite and nitroprusside sodium might possibly be due to the activation of the sGC after intermediate formation of S-nitroso substances from these substances and the thiols of the cells. The fact that the effect of organic nitrates depends on their metabolism and the thiol status of a cell could explain the development of tolerance towards organic nitrates. It was shown that S-nitroso substances such as the S-nitroso-N-acetyl penicillamines (SNAP) show no development of tolerance (Shaffer J E et al., J. Pharmacol. Exper. Ther. 260 (1992) 286-293) in vivo in an animal. It has been documented that the S-nitroso substances such as S-nitroso glutathion in vitro and in vivo have an anti-hypertensive and an anti-aggregatory effect in humans (De Belder et al., Cardiovasc. Res., 28 (1994) 691-694). For S-nitroso glutathion it was even shown that its anti-aggregatory component is by far more distinct than the anti-hypertensive one (De Belder et al., Cardiovasc. Res., 28 (1994) 691-694). For S-nitroso glutathion it was also shown that it reduces the rate of embolism in humans (Molloy et al., Circulation, 98 (1998) 1372-1375) and that this effect exceeds the one of acetylsalicylic acid and heparin.
The mechanisms of the anti-aggregatory effect of S-nitroso substances have not been clarified completely up until today. Apart from the cGMP-dependent mechanism, various cGMP-independent mechanisms have been discussed which are based on the influence of enzyme activitites or receptors by S-nitroso substances. It was shown, for example, that different S-nitroso substances and NO inhibit the enzymes glyceraldehyde-3-phophate-dehydrogenase (Padgett and Whorton, Am. J. Physiol. 269 (Cell Physiol. 38), (1995) C739-C749), phosphodiesterase (Maurice and Haslam R J, Molecular Pharmacol., 37 (1990) 671-681) and cyclooxygenase (Tsikas D et al., FEBS Lett., 442 (1999) 162-166).
The use of S-nitroso derivatives of ACE inhibitors and cysteine for the treatment of various diseases has been described by Loscalzo J and Cooke J (U.S. Pat. No. 5,025,001, 1991) as well as Stamler J S and Loscalzo J (International Application Number PCT/US92/03008).
At the moment, no S-nitroso and S-nitro substances are authorised as medicaments.
The problem underlying the present invention is to provide SNACE derivatives as pharmaceutical compositions or pharmaceutically active agents. The SNACE derivatives of the invention are particularly suitable for pharmaceutical preparations for the transdermal application sincexe2x80x94absorbed through the skin and after resorptionxe2x80x94they themselves or as metabolites (e.g. of hydrolases, deacylases) are effective as pro-drug directly or indirectly.
Thus, S-nitroso and S-nitro-N-acyl-L-cysteine ester derivatives with the general formula I 
are subject matter of the invention, wherein n=1 or N=2, x=0, 1 or 2, R1 is an alkyl group (C1-22) and R2 is an acyl group (C2-22) or O-acetylsalicyl group or an alkyl group (C1-22) as pharmacologically active agents.
S-Nitroso and S-nitro-N-acyl-L-cysteine ester derivatives with the general formula I.
Alkyl and acyl groups with up to 6 carbon atoms are preferred.
The methyl, ethyl, n-propyl and tert-butyl group are examples of alkyl groups. The acetyl priopionyl and tert-butyryl and O-acetylsalicyl group are examples of acyl groups.
The particularly preferred alkyl and acyl groups are the ethyl, acetyl and O-acetylsalicyl group due to the fact that their cleavage products ethanol, acetic acid and O-acetylsalicylic acid or salicylic acid are non-toxic.
The pharmacologically effective group of the compounds with the general formula I is the S-nitroso group (xe2x80x94Sxe2x80x94Nxe2x95x90O) or the S-nitro group (Sxe2x80x94NO2). The alkyl and acyl groups and the substituents at the sulphur of the compounds with the general formula I primarily influence the physicochemical properties, e.g. the penetration rate in the skin, and not so much their pharmacological activity.
The production of the compounds of the general formulae I and II is carried out according to methods known per se by esterification of the carboxyl group of cysteine and N-acylation or N-alkylation of the amino group of cysteine. Esters are produced e.g. by use of 3 M HCl in the corresponding water-free alcohols. N-acyl derivatives are produced e.g. by use of anhydrides of the corresponding carbon acids. N-alkyl derivatives are produced e.g. by use of alkyl halides. The compounds of the general formula II are the precursors of the corresponding compounds with the general formula I. The nitrosylation of the thiol group of cysteine derivatives of the general formula II takes place in hydrochloric acid-acidic solution by stoichiometric amounts of sodium nitrite (Tsikas et al., Anal. Biochem. 244 (1997) 208-220). The nitration of the thiol group of compounds of the general formula II takes place e.g. by use of nitronium tetrafluoroborate (Balazy et al., J. Biol. Chem. 273 (1998) 32009-32015).
Alternatively, the production of the compounds of the general formula I (n=1 or 2 and x=0) by S-transnitrosylation or S-transnitration of the thiol group of the corresponding cysteine derivative of the general formula II takes place by means of e.g. S-nitrosoglutathion or S-nitroglutathion (Tsikas et al., Anal. Biochem. 270 (1999) 231-241). This method can also be used for the in situ production of the compounds of the general formula I in the pharmacological composition. The SNACE derivatives with x=1 and x=2 are produced from the corresponding derivatives with x=0 by oxidation e.g. hydrogen peroxide.
The compounds with the general formula I can be used for the prevention of arteriosclerosis, for the treatment of hypertonia and pulmonic hypertonia, for the prevention and treatment of blood circulation disorders, e.g. of the brain, the heart and the extremities, for the inhibition of the platelet aggregation (thrombocyte aggregation), for the treatment of impotentia coeundi and for the treatment of asthma bronchiale, for the treatment of cystic fibrosis (mucoviscidosis) and of rejection reaction with transplants as well as cancer, homocysteinemia and for lipid reduction. Typical examples of disorders of the blood circulation of the brain are transitory cerebral ischemia, sudden deafness, dizziness due to circulation disorders and ischemic stroke. Typical examples of disorders of the blood circulation of the heart are angina pectoris and heart attack. Typical examples of blood circulation disorders of the extremities are peripheral artery blood circulation disorders with arteriosclerosis, M. Burgers and M. Raynaud as well as Raynaud""s syndrome.
Apart from the transdermal application, also the oral, rectal, intravenous or intra-arterial application as well as the inhalational application also in liposomes, micro-emulsions and micro-capsules can be considered for the compounds of the general formula I.
The production of pharmacological compositions takes place according to standard methods. For the production of pharmacological compositions for the transdermal application, the compounds of the general formula I can be used in the absence or in the presence of the corresponding compounds of the general formula II in a gel base, ointment base or a liquid base with or without different solution mediators, penetration accelerators as well as stabilisers. Sprays, tubes, ampuls as well as single portions can be used as primary packing material. After application onto the skin or with additional occlusion dressing, the active agent is absorbed.
Optionally, the compounds with the general formula I can also be applied with stabilisers as well as solution mediators on a plaster.